1. Field of the Invention
Embodiments of the invention relate to an image processing method, and more particularly, to an image processing method and apparatus for removing aliasing from a Bayer image.
2. Description of the Related Art
Digital image processing apparatuses, including an image sensor such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS), generally use an optical low-pass filter (OLPF) to remove high spatial frequency components from images. When a spatial frequency component, which is higher than a critical frequency in the images, is input into the digital image processing apparatuses, aliasing and a Moire pattern occurs in reproduced images. Here, the critical frequency corresponds to half the inverse number of a pixel period, and is referred to as a Nyquist frequency. An ideal OLPF removes all frequency components that are higher than the Nyquist frequency, and passes all frequency components that are lower than the Nyquist frequency.
In general, the OLPF is located in front of the CCD or the CMOS in digital cameras, digital camcorders, and surveillance cameras to remove high spatial frequency components, and thus, the aliasing and the Moire pattern are removed to improve the quality of images. However, the OLPF may be expensive and may have difficulty with reduction and pixel noise.